| 摘要 |
<p>The invention relates to plasticizing screws for use in screw extruders A problem with known screws and extruders is that the quality and uniformity of the extrudate is poor, with implasticised material being encapsulated in the melt.
<??>The screw shown has a first flight (33, 37) which extends through a feed section (35) and a plasticizing section (40), and a second flight (36) which extends through the plasticizing section. The flights define a feed channel (34), a solids channel (39) and a melt channel (38). The solids channel (39) has an initial depth greater than the depth of the feed channel (34) and receives any solid material from the feed channel. Thereafter, the depth of the solids channel is reduced, and the diameters of the flights allow plasticized material to pass from the solids channel to the (39) melt channel (38).</p> |
